In current packet data communication systems Soft HandOver (SHO) is used for downlink packet services, and packet scheduling is done periodically. However, studies have shown that SHO is not always beneficial for packet services.
From the interference point of view it is not desirable to have SHO in the downlink. For instance, it is very rare that the average propagation loss coming from multiple Base Stations (BSs) are the same, resulting into poor multipath combining at the RAKE receiver.
Moreover, packet transmissions are shorter compared to circuit-switched calls, and seamless connection is also not mandatory. Oftentimes, a packet Mobile Station (MS) is in the DTX (Discontinuous Transmission) mode, and performing unnecessary SHO updates during DTX does not contribute to the system performance.
Hence, using SHO for downlink packet services does not necessarily improve the system capacity but rather introduces a large amount of signaling.